This standard specifies a method for determining the density of non-foam plastics by gas-specific gravity meters. The density of plastics is calculated by placing the sample in a gas-specific gravity meter, measuring the change in gas volume and the mass of the sample of a known volume. The sample can be in powder, granular, flake or thin sheet, and the gas-specific gravity meter should be equipped with a thermostatic control device to ensure accurate measurement. This method is suitable for a variety of solid non-foam plastics and helps to accurately determine their physical performance.